Amino Acid Changes in Thiamine-Deficient Encephalopathy: Some Implications for the Pathogenesis of Friedreich's Ataxia

Abstract

SummaryThiamine-deficient encephalopathy in the rat is characterized by ataxie gait, loss of righting reflex and curvature of the spine. N euro chemie ai changes include a diminished activity of cerebral pyruvate decarboxylase leading to abnormal pyruvate oxidation. The present study shows that this defective pyruvate oxidation produces a significant depletion of three important amino acid neurotransmitters, namely gamma aminobuiyrie acid (GABA), glutamic acid, andaspartic acid. Such changes could lead to severe neuronal dysfunction and the observed neurological symptoms of thiamine deficiency. Some implications for the pathogenesis of Friedreich's ataxia are discussed.